/*
* Vulkan Example - Offscreen rendering using a separate framebuffer
*
* Copyright (C) 2016-2025 Sascha Willems - www.saschawillems.de
*
* This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
*/

#include "vulkanexamplebase.h"
#include "VulkanglTFModel.h"

// Offscreen frame buffer properties
#define FB_DIM 512
#define FB_COLOR_FORMAT VK_FORMAT_R8G8B8A8_UNORM

class VulkanExample : public VulkanExampleBase
{
public:
	bool debugDisplay = false;

	struct {
		vkglTF::Model example;
		vkglTF::Model plane;
	} models;

	struct UniformData {
		glm::mat4 projection;
		glm::mat4 view;
		glm::mat4 model;
		glm::vec4 lightPos = glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
	} uniformData;

	struct UniformBuffers {
		vks::Buffer model;
		vks::Buffer mirror;
		vks::Buffer offscreen;
	};
	std::array<UniformBuffers, maxConcurrentFrames> uniformBuffers;

	struct {
		VkPipelineLayout textured{ VK_NULL_HANDLE };
		VkPipelineLayout shaded{ VK_NULL_HANDLE };
	} pipelineLayouts;

	struct {
		VkPipeline debug{ VK_NULL_HANDLE };
		VkPipeline shaded{ VK_NULL_HANDLE };
		VkPipeline shadedOffscreen{ VK_NULL_HANDLE };
		VkPipeline mirror{ VK_NULL_HANDLE };
	} pipelines;

	struct {
		VkDescriptorSetLayout textured{ VK_NULL_HANDLE };
		VkDescriptorSetLayout shaded{ VK_NULL_HANDLE };
	} descriptorSetLayouts;

	struct DescriptorSets {
		VkDescriptorSet offscreen{ VK_NULL_HANDLE };
		VkDescriptorSet mirror{ VK_NULL_HANDLE };
		VkDescriptorSet model{ VK_NULL_HANDLE };
	};
	std::array<DescriptorSets, maxConcurrentFrames> descriptorSets;

	// Framebuffer for offscreen rendering
	struct FrameBufferAttachment {
		VkImage image;
		VkDeviceMemory mem;
		VkImageView view;
	};
	struct OffscreenPass {
		int32_t width, height;
		VkFramebuffer frameBuffer;
		FrameBufferAttachment color, depth;
		VkRenderPass renderPass;
		VkSampler sampler;
		VkDescriptorImageInfo descriptor;
	} offscreenPass{};

	glm::vec3 modelPosition = glm::vec3(0.0f, -1.0f, 0.0f);
	glm::vec3 modelRotation = glm::vec3(0.0f);

	VulkanExample() : VulkanExampleBase()
	{
		title = "Offscreen rendering";
		timerSpeed *= 0.25f;
		camera.type = Camera::CameraType::lookat;
		camera.setPosition(glm::vec3(0.0f, 1.0f, -6.0f));
		camera.setRotation(glm::vec3(-2.5f, 0.0f, 0.0f));
		camera.setRotationSpeed(0.5f);
		camera.setPerspective(60.0f, (float)width / (float)height, 0.1f, 256.0f);
		// The scene shader uses a clipping plane, so this feature has to be enabled
		enabledFeatures.shaderClipDistance = VK_TRUE;
	}

	~VulkanExample()
	{
		if (device) {
			vkDestroyImageView(device, offscreenPass.color.view, nullptr);
			vkDestroyImage(device, offscreenPass.color.image, nullptr);
			vkFreeMemory(device, offscreenPass.color.mem, nullptr);
			vkDestroyImageView(device, offscreenPass.depth.view, nullptr);
			vkDestroyImage(device, offscreenPass.depth.image, nullptr);
			vkFreeMemory(device, offscreenPass.depth.mem, nullptr);
			vkDestroyRenderPass(device, offscreenPass.renderPass, nullptr);
			vkDestroySampler(device, offscreenPass.sampler, nullptr);
			vkDestroyFramebuffer(device, offscreenPass.frameBuffer, nullptr);
			vkDestroyPipeline(device, pipelines.debug, nullptr);
			vkDestroyPipeline(device, pipelines.shaded, nullptr);
			vkDestroyPipeline(device, pipelines.shadedOffscreen, nullptr);
			vkDestroyPipeline(device, pipelines.mirror, nullptr);
			vkDestroyPipelineLayout(device, pipelineLayouts.textured, nullptr);
			vkDestroyPipelineLayout(device, pipelineLayouts.shaded, nullptr);
			vkDestroyDescriptorSetLayout(device, descriptorSetLayouts.shaded, nullptr);
			vkDestroyDescriptorSetLayout(device, descriptorSetLayouts.textured, nullptr);
			for (auto& buffer : uniformBuffers) {
				buffer.model.destroy();
				buffer.mirror.destroy();
				buffer.offscreen.destroy();
			}
		}
	}

	// Setup the offscreen framebuffer for rendering the mirrored scene
	// The color attachment of this framebuffer will then be used to sample from in the fragment shader of the final pass
	void prepareOffscreen()
	{
		offscreenPass.width = FB_DIM;
		offscreenPass.height = FB_DIM;

		// Find a suitable depth format
		VkFormat fbDepthFormat;
		VkBool32 validDepthFormat = vks::tools::getSupportedDepthFormat(physicalDevice, &fbDepthFormat);
		assert(validDepthFormat);

		// Color attachment
		VkImageCreateInfo image = vks::initializers::imageCreateInfo();
		image.imageType = VK_IMAGE_TYPE_2D;
		image.format = FB_COLOR_FORMAT;
		image.extent.width = offscreenPass.width;
		image.extent.height = offscreenPass.height;
		image.extent.depth = 1;
		image.mipLevels = 1;
		image.arrayLayers = 1;
		image.samples = VK_SAMPLE_COUNT_1_BIT;
		image.tiling = VK_IMAGE_TILING_OPTIMAL;
		// We will sample directly from the color attachment
		image.usage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT | VK_IMAGE_USAGE_SAMPLED_BIT;

		VkMemoryAllocateInfo memAlloc = vks::initializers::memoryAllocateInfo();
		VkMemoryRequirements memReqs;

		VK_CHECK_RESULT(vkCreateImage(device, &image, nullptr, &offscreenPass.color.image));
		vkGetImageMemoryRequirements(device, offscreenPass.color.image, &memReqs);
		memAlloc.allocationSize = memReqs.size;
		memAlloc.memoryTypeIndex = vulkanDevice->getMemoryType(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT);
		VK_CHECK_RESULT(vkAllocateMemory(device, &memAlloc, nullptr, &offscreenPass.color.mem));
		VK_CHECK_RESULT(vkBindImageMemory(device, offscreenPass.color.image, offscreenPass.color.mem, 0));

		VkImageViewCreateInfo colorImageView = vks::initializers::imageViewCreateInfo();
		colorImageView.viewType = VK_IMAGE_VIEW_TYPE_2D;
		colorImageView.format = FB_COLOR_FORMAT;
		colorImageView.subresourceRange = {};
		colorImageView.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
		colorImageView.subresourceRange.baseMipLevel = 0;
		colorImageView.subresourceRange.levelCount = 1;
		colorImageView.subresourceRange.baseArrayLayer = 0;
		colorImageView.subresourceRange.layerCount = 1;
		colorImageView.image = offscreenPass.color.image;
		VK_CHECK_RESULT(vkCreateImageView(device, &colorImageView, nullptr, &offscreenPass.color.view));

		// Create sampler to sample from the attachment in the fragment shader
		VkSamplerCreateInfo samplerInfo = vks::initializers::samplerCreateInfo();
		samplerInfo.magFilter = VK_FILTER_LINEAR;
		samplerInfo.minFilter = VK_FILTER_LINEAR;
		samplerInfo.mipmapMode = VK_SAMPLER_MIPMAP_MODE_LINEAR;
		samplerInfo.addressModeU = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
		samplerInfo.addressModeV = samplerInfo.addressModeU;
		samplerInfo.addressModeW = samplerInfo.addressModeU;
		samplerInfo.mipLodBias = 0.0f;
		samplerInfo.maxAnisotropy = 1.0f;
		samplerInfo.minLod = 0.0f;
		samplerInfo.maxLod = 1.0f;
		samplerInfo.borderColor = VK_BORDER_COLOR_FLOAT_OPAQUE_WHITE;
		VK_CHECK_RESULT(vkCreateSampler(device, &samplerInfo, nullptr, &offscreenPass.sampler));

		// Depth stencil attachment
		image.format = fbDepthFormat;
		image.usage = VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT;

		VK_CHECK_RESULT(vkCreateImage(device, &image, nullptr, &offscreenPass.depth.image));
		vkGetImageMemoryRequirements(device, offscreenPass.depth.image, &memReqs);
		memAlloc.allocationSize = memReqs.size;
		memAlloc.memoryTypeIndex = vulkanDevice->getMemoryType(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT);
		VK_CHECK_RESULT(vkAllocateMemory(device, &memAlloc, nullptr, &offscreenPass.depth.mem));
		VK_CHECK_RESULT(vkBindImageMemory(device, offscreenPass.depth.image, offscreenPass.depth.mem, 0));

		VkImageViewCreateInfo depthStencilView = vks::initializers::imageViewCreateInfo();
		depthStencilView.viewType = VK_IMAGE_VIEW_TYPE_2D;
		depthStencilView.format = fbDepthFormat;
		depthStencilView.flags = 0;
		depthStencilView.subresourceRange = {};
		depthStencilView.subresourceRange.aspectMask = VK_IMAGE_ASPECT_DEPTH_BIT;
		if (fbDepthFormat >= VK_FORMAT_D16_UNORM_S8_UINT) {
			depthStencilView.subresourceRange.aspectMask |= VK_IMAGE_ASPECT_STENCIL_BIT;
		}
		depthStencilView.subresourceRange.baseMipLevel = 0;
		depthStencilView.subresourceRange.levelCount = 1;
		depthStencilView.subresourceRange.baseArrayLayer = 0;
		depthStencilView.subresourceRange.layerCount = 1;
		depthStencilView.image = offscreenPass.depth.image;
		VK_CHECK_RESULT(vkCreateImageView(device, &depthStencilView, nullptr, &offscreenPass.depth.view));

		// Create a separate render pass for the offscreen rendering as it may differ from the one used for scene rendering

		std::array<VkAttachmentDescription, 2> attchmentDescriptions = {};
		// Color attachment
		attchmentDescriptions[0].format = FB_COLOR_FORMAT;
		attchmentDescriptions[0].samples = VK_SAMPLE_COUNT_1_BIT;
		attchmentDescriptions[0].loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
		attchmentDescriptions[0].storeOp = VK_ATTACHMENT_STORE_OP_STORE;
		attchmentDescriptions[0].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
		attchmentDescriptions[0].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
		attchmentDescriptions[0].initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
		attchmentDescriptions[0].finalLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
		// Depth attachment
		attchmentDescriptions[1].format = fbDepthFormat;
		attchmentDescriptions[1].samples = VK_SAMPLE_COUNT_1_BIT;
		attchmentDescriptions[1].loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
		attchmentDescriptions[1].storeOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
		attchmentDescriptions[1].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
		attchmentDescriptions[1].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
		attchmentDescriptions[1].initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
		attchmentDescriptions[1].finalLayout = VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;

		VkAttachmentReference colorReference = { 0, VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL };
		VkAttachmentReference depthReference = { 1, VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL };

		VkSubpassDescription subpassDescription = {};
		subpassDescription.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
		subpassDescription.colorAttachmentCount = 1;
		subpassDescription.pColorAttachments = &colorReference;
		subpassDescription.pDepthStencilAttachment = &depthReference;

		// Use subpass dependencies for layout transitions
		std::array<VkSubpassDependency, 2> dependencies;

		dependencies[0].srcSubpass = VK_SUBPASS_EXTERNAL;
		dependencies[0].dstSubpass = 0;
		dependencies[0].srcStageMask = VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT;
		dependencies[0].dstStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT | VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT | VK_PIPELINE_STAGE_LATE_FRAGMENT_TESTS_BIT;
		dependencies[0].srcAccessMask = VK_ACCESS_NONE_KHR;
		dependencies[0].dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_READ_BIT | VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT | VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_READ_BIT | VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT;
		dependencies[0].dependencyFlags = VK_DEPENDENCY_BY_REGION_BIT;

		dependencies[1].srcSubpass = 0;
		dependencies[1].dstSubpass = VK_SUBPASS_EXTERNAL;
		dependencies[1].srcStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT | VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT | VK_PIPELINE_STAGE_LATE_FRAGMENT_TESTS_BIT;
		dependencies[1].dstStageMask = VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT;
		dependencies[1].srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_READ_BIT | VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT | VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_READ_BIT | VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT;
		dependencies[1].dstAccessMask = VK_ACCESS_MEMORY_READ_BIT;
		dependencies[1].dependencyFlags = VK_DEPENDENCY_BY_REGION_BIT;

		// Create the actual renderpass
		VkRenderPassCreateInfo renderPassInfo = {};
		renderPassInfo.sType = VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO;
		renderPassInfo.attachmentCount = static_cast<uint32_t>(attchmentDescriptions.size());
		renderPassInfo.pAttachments = attchmentDescriptions.data();
		renderPassInfo.subpassCount = 1;
		renderPassInfo.pSubpasses = &subpassDescription;
		renderPassInfo.dependencyCount = static_cast<uint32_t>(dependencies.size());
		renderPassInfo.pDependencies = dependencies.data();

		VK_CHECK_RESULT(vkCreateRenderPass(device, &renderPassInfo, nullptr, &offscreenPass.renderPass));

		VkImageView attachments[2];
		attachments[0] = offscreenPass.color.view;
		attachments[1] = offscreenPass.depth.view;

		VkFramebufferCreateInfo fbufCreateInfo = vks::initializers::framebufferCreateInfo();
		fbufCreateInfo.renderPass = offscreenPass.renderPass;
		fbufCreateInfo.attachmentCount = 2;
		fbufCreateInfo.pAttachments = attachments;
		fbufCreateInfo.width = offscreenPass.width;
		fbufCreateInfo.height = offscreenPass.height;
		fbufCreateInfo.layers = 1;

		VK_CHECK_RESULT(vkCreateFramebuffer(device, &fbufCreateInfo, nullptr, &offscreenPass.frameBuffer));

		// Fill a descriptor for later use in a descriptor set
		offscreenPass.descriptor.imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
		offscreenPass.descriptor.imageView = offscreenPass.color.view;
		offscreenPass.descriptor.sampler = offscreenPass.sampler;
	}

	void loadAssets()
	{
		const uint32_t glTFLoadingFlags = vkglTF::FileLoadingFlags::PreTransformVertices | vkglTF::FileLoadingFlags::PreMultiplyVertexColors | vkglTF::FileLoadingFlags::FlipY;
		models.plane.loadFromFile(getAssetPath() + "models/plane.gltf", vulkanDevice, queue, glTFLoadingFlags);
		models.example.loadFromFile(getAssetPath() + "models/chinesedragon.gltf", vulkanDevice, queue, glTFLoadingFlags);
	}

	void setupDescriptors()
	{
		// Pool
		std::vector<VkDescriptorPoolSize> poolSizes = {
			vks::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, maxConcurrentFrames * 3),
			vks::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, maxConcurrentFrames * 2)
		};
		VkDescriptorPoolCreateInfo descriptorPoolInfo = vks::initializers::descriptorPoolCreateInfo(poolSizes, maxConcurrentFrames * 3);
		VK_CHECK_RESULT(vkCreateDescriptorPool(device, &descriptorPoolInfo, nullptr, &descriptorPool));

		// Layout
		std::vector<VkDescriptorSetLayoutBinding> setLayoutBindings;
		VkDescriptorSetLayoutCreateInfo descriptorLayoutInfo;

		// Shaded layout
		setLayoutBindings = {
			// Binding 0 : Vertex shader uniform buffer
			vks::initializers::descriptorSetLayoutBinding(VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, VK_SHADER_STAGE_VERTEX_BIT, 0),
		};
		descriptorLayoutInfo = vks::initializers::descriptorSetLayoutCreateInfo(setLayoutBindings);
		VK_CHECK_RESULT(vkCreateDescriptorSetLayout(device, &descriptorLayoutInfo, nullptr, &descriptorSetLayouts.shaded));

		// Textured layouts
		setLayoutBindings = {
			// Binding 0 : Vertex shader uniform buffer
			vks::initializers::descriptorSetLayoutBinding(VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, VK_SHADER_STAGE_VERTEX_BIT, 0),
			// Binding 1 : Fragment shader image sampler
			vks::initializers::descriptorSetLayoutBinding(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, VK_SHADER_STAGE_FRAGMENT_BIT, 1)
		};
		descriptorLayoutInfo = vks::initializers::descriptorSetLayoutCreateInfo(setLayoutBindings);
		VK_CHECK_RESULT(vkCreateDescriptorSetLayout(device, &descriptorLayoutInfo, nullptr, &descriptorSetLayouts.textured));

		// Sets per frame, just like the buffers themselves
		// Images do not need to be duplicated per frame, we reuse the same one for each frame
		for (auto i = 0; i < uniformBuffers.size(); i++) {
			// Mirror plane descriptor set
			VkDescriptorSetAllocateInfo allocInfo = vks::initializers::descriptorSetAllocateInfo(descriptorPool, &descriptorSetLayouts.textured, 1);
			VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &descriptorSets[i].mirror));
			std::vector<VkWriteDescriptorSet> writeDescriptorSets = {
				// Binding 0 : Vertex shader uniform buffer
				vks::initializers::writeDescriptorSet(descriptorSets[i].mirror, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 0, &uniformBuffers[i].mirror.descriptor),
				// Binding 1 : Fragment shader texture sampler
				vks::initializers::writeDescriptorSet(descriptorSets[i].mirror, VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 1, &offscreenPass.descriptor),
			};
			vkUpdateDescriptorSets(device, static_cast<uint32_t>(writeDescriptorSets.size()), writeDescriptorSets.data(), 0, nullptr);

			// Shaded descriptor sets
			allocInfo = vks::initializers::descriptorSetAllocateInfo(descriptorPool, &descriptorSetLayouts.shaded, 1);
			// Model
			VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &descriptorSets[i].model));
			std::vector<VkWriteDescriptorSet> modelWriteDescriptorSets = {
				// Binding 0 : Vertex shader uniform buffer
				vks::initializers::writeDescriptorSet(descriptorSets[i].model, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 0, &uniformBuffers[i].model.descriptor)
			};
			vkUpdateDescriptorSets(device, static_cast<uint32_t>(modelWriteDescriptorSets.size()), modelWriteDescriptorSets.data(), 0, nullptr);

			// Offscreen
			VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &descriptorSets[i].offscreen));
			std::vector<VkWriteDescriptorSet> offScreenWriteDescriptorSets = {
				// Binding 0 : Vertex shader uniform buffer
				vks::initializers::writeDescriptorSet(descriptorSets[i].offscreen, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 0, &uniformBuffers[i].offscreen.descriptor)
			};
			vkUpdateDescriptorSets(device, static_cast<uint32_t>(offScreenWriteDescriptorSets.size()), offScreenWriteDescriptorSets.data(), 0, nullptr);
		}
	}

	void preparePipelines()
	{
		// Layouts
		VkPipelineLayoutCreateInfo pipelineLayoutInfo = vks::initializers::pipelineLayoutCreateInfo(&descriptorSetLayouts.shaded, 1);
		VK_CHECK_RESULT(vkCreatePipelineLayout(device, &pipelineLayoutInfo, nullptr, &pipelineLayouts.shaded));

		pipelineLayoutInfo = vks::initializers::pipelineLayoutCreateInfo(&descriptorSetLayouts.textured, 1);
		VK_CHECK_RESULT(vkCreatePipelineLayout(device, &pipelineLayoutInfo, nullptr, &pipelineLayouts.textured));

		// Pipelines
		VkPipelineInputAssemblyStateCreateInfo inputAssemblyState = vks::initializers::pipelineInputAssemblyStateCreateInfo(VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST, 0, VK_FALSE);
 		VkPipelineRasterizationStateCreateInfo rasterizationState = vks::initializers::pipelineRasterizationStateCreateInfo(VK_POLYGON_MODE_FILL, VK_CULL_MODE_BACK_BIT, VK_FRONT_FACE_COUNTER_CLOCKWISE,0);
		VkPipelineColorBlendAttachmentState blendAttachmentState = vks::initializers::pipelineColorBlendAttachmentState(0xf, VK_FALSE);
		VkPipelineColorBlendStateCreateInfo colorBlendState = vks::initializers::pipelineColorBlendStateCreateInfo(1, &blendAttachmentState);
		VkPipelineDepthStencilStateCreateInfo depthStencilState = vks::initializers::pipelineDepthStencilStateCreateInfo(VK_TRUE, VK_TRUE, VK_COMPARE_OP_LESS_OR_EQUAL);
		VkPipelineViewportStateCreateInfo viewportState = vks::initializers::pipelineViewportStateCreateInfo(1, 1, 0);
		VkPipelineMultisampleStateCreateInfo multisampleState = vks::initializers::pipelineMultisampleStateCreateInfo(VK_SAMPLE_COUNT_1_BIT, 0);
		std::vector<VkDynamicState> dynamicStateEnables = {VK_DYNAMIC_STATE_VIEWPORT, VK_DYNAMIC_STATE_SCISSOR};
		VkPipelineDynamicStateCreateInfo dynamicState = vks::initializers::pipelineDynamicStateCreateInfo(dynamicStateEnables);
		std::array<VkPipelineShaderStageCreateInfo, 2> shaderStages{};

		VkGraphicsPipelineCreateInfo pipelineCI = vks::initializers::pipelineCreateInfo(pipelineLayouts.textured, renderPass, 0);
		pipelineCI.pInputAssemblyState = &inputAssemblyState;
		pipelineCI.pRasterizationState = &rasterizationState;
		pipelineCI.pColorBlendState = &colorBlendState;
		pipelineCI.pMultisampleState = &multisampleState;
		pipelineCI.pViewportState = &viewportState;
		pipelineCI.pDepthStencilState = &depthStencilState;
		pipelineCI.pDynamicState = &dynamicState;
		pipelineCI.stageCount = static_cast<uint32_t>(shaderStages.size());
		pipelineCI.pStages = shaderStages.data();
		pipelineCI.pVertexInputState = vkglTF::Vertex::getPipelineVertexInputState({vkglTF::VertexComponent::Position, vkglTF::VertexComponent::Color, vkglTF::VertexComponent::Normal});

		rasterizationState.cullMode = VK_CULL_MODE_NONE;

		// Render-target debug display
		shaderStages[0] = loadShader(getShadersPath() + "offscreen/quad.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
		shaderStages[1] = loadShader(getShadersPath() + "offscreen/quad.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipelines.debug));

		// Mirror
		shaderStages[0] = loadShader(getShadersPath() + "offscreen/mirror.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
		shaderStages[1] = loadShader(getShadersPath() + "offscreen/mirror.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipelines.mirror));

		rasterizationState.cullMode = VK_CULL_MODE_BACK_BIT;

		// Phong shading pipelines
		pipelineCI.layout = pipelineLayouts.shaded;
		// Scene
		shaderStages[0] = loadShader(getShadersPath() + "offscreen/phong.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
		shaderStages[1] = loadShader(getShadersPath() + "offscreen/phong.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipelines.shaded));
		// Offscreen
		// Flip cull mode
		rasterizationState.cullMode = VK_CULL_MODE_FRONT_BIT;
		pipelineCI.renderPass = offscreenPass.renderPass;
		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipelines.shadedOffscreen));

	}

	// Prepare and initialize uniform buffer containing shader uniforms
	void prepareUniformBuffers()
	{
		for (auto& buffer : uniformBuffers) {
			// Mesh vertex shader uniform buffer block
			VK_CHECK_RESULT(vulkanDevice->createBuffer(VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, &buffer.model, sizeof(UniformData)));
			VK_CHECK_RESULT(buffer.model.map());
			// Mirror plane vertex shader uniform buffer block
			VK_CHECK_RESULT(vulkanDevice->createBuffer(VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, &buffer.mirror, sizeof(UniformData)));
			VK_CHECK_RESULT(buffer.mirror.map());
			// Offscreen vertex shader uniform buffer block
			VK_CHECK_RESULT(vulkanDevice->createBuffer(VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, &buffer.offscreen, sizeof(UniformData)));
			VK_CHECK_RESULT(buffer.offscreen.map());
		}
	}

	void updateUniformBuffers()
	{
		if (!paused) {
			modelRotation.y += frameTimer * 10.0f;
		}

		uniformData.projection = camera.matrices.perspective;
		uniformData.view = camera.matrices.view;

		// Model
		uniformData.model = glm::mat4(1.0f);
		uniformData.model = glm::rotate(uniformData.model, glm::radians(modelRotation.y), glm::vec3(0.0f, 1.0f, 0.0f));
		uniformData.model = glm::translate(uniformData.model, modelPosition);
		memcpy(uniformBuffers[currentBuffer].model.mapped, &uniformData, sizeof(UniformData));

		// Mirror
		uniformData.model = glm::mat4(1.0f);
		memcpy(uniformBuffers[currentBuffer].mirror.mapped, &uniformData, sizeof(UniformData));

		uniformData.model = glm::mat4(1.0f);
		uniformData.model = glm::rotate(uniformData.model, glm::radians(modelRotation.y), glm::vec3(0.0f, 1.0f, 0.0f));
		uniformData.model = glm::scale(uniformData.model, glm::vec3(1.0f, -1.0f, 1.0f));
		uniformData.model = glm::translate(uniformData.model, modelPosition);
		memcpy(uniformBuffers[currentBuffer].offscreen.mapped, &uniformData, sizeof(UniformData));

	}

	void updateUniformBufferOffscreen()
	{
	}

	void prepare()
	{
		VulkanExampleBase::prepare();
		loadAssets();
		prepareOffscreen();
		prepareUniformBuffers();
		setupDescriptors();
		preparePipelines();
		prepared = true;
	}

	void buildCommandBuffer()
	{
		VkCommandBuffer cmdBuffer = drawCmdBuffers[currentBuffer];
		
		VkCommandBufferBeginInfo cmdBufInfo = vks::initializers::commandBufferBeginInfo();

		VK_CHECK_RESULT(vkBeginCommandBuffer(cmdBuffer, &cmdBufInfo));

		/*
			First render pass: Offscreen rendering
		*/
		{
			VkClearValue clearValues[2]{};
			clearValues[0].color = { { 0.0f, 0.0f, 0.0f, 0.0f } };
			clearValues[1].depthStencil = { 1.0f, 0 };

			VkRenderPassBeginInfo renderPassBeginInfo = vks::initializers::renderPassBeginInfo();
			renderPassBeginInfo.renderPass = offscreenPass.renderPass;
			renderPassBeginInfo.framebuffer = offscreenPass.frameBuffer;
			renderPassBeginInfo.renderArea.extent.width = offscreenPass.width;
			renderPassBeginInfo.renderArea.extent.height = offscreenPass.height;
			renderPassBeginInfo.clearValueCount = 2;
			renderPassBeginInfo.pClearValues = clearValues;

			vkCmdBeginRenderPass(cmdBuffer, &renderPassBeginInfo, VK_SUBPASS_CONTENTS_INLINE);

			VkViewport viewport = vks::initializers::viewport((float)offscreenPass.width, (float)offscreenPass.height, 0.0f, 1.0f);
			vkCmdSetViewport(cmdBuffer, 0, 1, &viewport);

			VkRect2D scissor = vks::initializers::rect2D(offscreenPass.width, offscreenPass.height, 0, 0);
			vkCmdSetScissor(cmdBuffer, 0, 1, &scissor);

			// Mirrored scene
			vkCmdBindDescriptorSets(cmdBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayouts.shaded, 0, 1, &descriptorSets[currentBuffer].offscreen, 0, nullptr);
			vkCmdBindPipeline(cmdBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelines.shadedOffscreen);
			models.example.draw(cmdBuffer);

			vkCmdEndRenderPass(cmdBuffer);
		}

		/*
			Note: Explicit synchronization is not required between the render pass, as this is done implicit via sub pass dependencies
		*/

		/*
			Second render pass: Scene rendering with applied radial blur
		*/
		{
			VkClearValue clearValues[2]{};
			clearValues[0].color = defaultClearColor;
			clearValues[1].depthStencil = { 1.0f, 0 };

			VkRenderPassBeginInfo renderPassBeginInfo = vks::initializers::renderPassBeginInfo();
			renderPassBeginInfo.renderPass = renderPass;
			renderPassBeginInfo.framebuffer = frameBuffers[currentImageIndex];
			renderPassBeginInfo.renderArea.extent.width = width;
			renderPassBeginInfo.renderArea.extent.height = height;
			renderPassBeginInfo.clearValueCount = 2;
			renderPassBeginInfo.pClearValues = clearValues;

			vkCmdBeginRenderPass(cmdBuffer, &renderPassBeginInfo, VK_SUBPASS_CONTENTS_INLINE);

			VkViewport viewport = vks::initializers::viewport((float)width, (float)height, 0.0f, 1.0f);
			vkCmdSetViewport(cmdBuffer, 0, 1, &viewport);

			VkRect2D scissor = vks::initializers::rect2D(width, height, 0, 0);
			vkCmdSetScissor(cmdBuffer, 0, 1, &scissor);

			if (debugDisplay)
			{
				// Display the offscreen render target
				vkCmdBindDescriptorSets(cmdBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayouts.textured, 0, 1, &descriptorSets[currentBuffer].mirror, 0, nullptr);
				vkCmdBindPipeline(cmdBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelines.debug);
				vkCmdDraw(cmdBuffer, 3, 1, 0, 0);
			}
			else {
				// Render the scene
				// Reflection plane
				vkCmdBindDescriptorSets(cmdBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayouts.textured, 0, 1, &descriptorSets[currentBuffer].mirror, 0, nullptr);
				vkCmdBindPipeline(cmdBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelines.mirror);
				models.plane.draw(cmdBuffer);
				// Model
				vkCmdBindDescriptorSets(cmdBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayouts.shaded, 0, 1, &descriptorSets[currentBuffer].model, 0, nullptr);
				vkCmdBindPipeline(cmdBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelines.shaded);
				models.example.draw(cmdBuffer);
			}

			drawUI(cmdBuffer);

			vkCmdEndRenderPass(cmdBuffer);
		}

		VK_CHECK_RESULT(vkEndCommandBuffer(cmdBuffer));
	}

	virtual void render()
	{
		if (!prepared)
			return;
		VulkanExampleBase::prepareFrame();
		updateUniformBuffers();
		buildCommandBuffer();
		VulkanExampleBase::submitFrame();
	}

	virtual void OnUpdateUIOverlay(vks::UIOverlay *overlay)
	{
		if (overlay->header("Settings")) {
			overlay->checkBox("Display render target", &debugDisplay);
		}
	}
};

VULKAN_EXAMPLE_MAIN()
